Production of lubricating oils from resin extracts



51m@ 27, 1967 M. T. sMlLsKl ETAL PRODUCTION OF' LUBRICATING OILS FROMRESIN EXTRACTS Filed June 2, 1966 A /fO/ney Wox United States Patent O3,328,287 PRODUCTHN OF LUBRECATING OILS FROM RESIN EXTRACTS Michael T.Smilski, Mantua Township, and Henry R. 1relaud, West Deptford Township,Gloucester County, N .3., assignors to Mobil Oil Corporation, acorporation of New York Filed .lune 2, 1966, Ser. No. 554,857 9 Claims.(Cl. 208-87) This application is a continuation-in-part of Ser. No.285,331 led June 4, 1963, now abandoned.

This invention relates to the preparation of lubricating oil and in aparticular aspect relates to a process for the preparation of widetemperature range lubricating oils as well as multi-grade lubricatingoils.

Mineral lubricating oils, known as multi-viscosity or multi-gradelubricating oils, are lubricating oils capable of meeting more than one,such as two or more viscosity grade specifications of the Society ofAutomotive Engineers (SAE). Such oils are desirable and essential whenit is necessary to have a lubricant of sufficiently low viscosity at lowtemperatures to provide desired lubrication and of sufficiently highviscosity at considerably higher temperatures to also providesatisfactory lubrication at the higher temperatures.

However, lubricants particularly suitable for jet aircraft enginesdilfer from multi-grade automotive lubricants in that they are requiredto lubricate and cool gears and bearings under relatively widetemperature conditions. Unlike piston engine lubes, gas turbine lubesemployed in jet engines are contaminated substantially less with fueland/ or combustion deposits. However, they, ou the other hand, aresubjected to very high temperatures under oxidizing conditions and mustalso be useable at low temperatures. Generally speaking, jet enginesoperate at bulk oil temperatures of about 250 F. and bearingtemperatures of the order of about 450-500 F. However, much higheroperating temperatures are contemplated for the future, For example,bulk oil temperatures of about 500 F. are visualized for more advancedengine designs because of higher power output and increased aerodynamicheating effects.

At the present time wide temperature range lubricants for jet enginesare being made by methods which include their preparation from chemicalmaterials such as organic esters, glycols, silicons, polyolens andhalogenated hydrocarbons. These materials, however, are substantiallymore expensive than mineral oil base lubricants and have certainshortcomings in performance standards. Generally speaking, the syntheticlubricants are less satisfactory than petroleum lubricants in one ormore of the following, including viscosity, temperature characteristics,volatility, tlammability, oxidization stability, thermal stability,lubricating characteristics and costs.

Another method of obtaining multi-viscosity lube oils is by the additionof certain synthetic organic compounds known as viscosity indeximprovers to oils which are added in an amount sufficient to meetmulti-grade specilications. However, these viscosity improver materialsare objectionable because of costs and perhaps more importantly theirinstability during use. In addition to the above methods of preparation,lubricating oils have also been prepared from relatively high boilinghydrocarbon fractions composed of paraflinic and naphthenic hydrocarbonscontaining isomeric molecules. These 'high boiling hydrocarbons,however, contain yconstituents which must be removed before the oil issuitable for lubricating purposes. Accordingly, in the prior artpractice, a desired oil fraction is dewaxed by mixing with a suitablesolvent such as a mixture of toluene, benzene and acetone, after whichthe mixture is cooled until the wax therein crystallizes.V

Filtering is employed to remove the precipitated wax and thereafter theSolvent is separated and recovered from the oil. Heavy oils andparticularly those boiling above about 900 F. and remaining after theremoval of distillate boiling range material suitable for lubricatingoils are known as cylinder stocks. The cylinder stock is thereaftersubjected to a solvent dewaxing step and a step to remove resintherefrom to produce a deresined stock known as a Bright stock. The thusprepared Bright stock is used for blending with dewaxed lighter oils toform heavier grades of lubricating oils. In the treatment of cylinderstock for the preparation of Bright stock, resinous material andaromatic constituents are removed from the relatively high boilingpetroleum fractions to produce a parafnic Bright stock and there isrecovered therefrom an extract phase or extract fraction known as theresin extract. Heretofore this resin extract fraction has been disposedof by burning as a fuel or disposed of by other suitable means.

It is an object of this invention to prepare wide temperature rangelubricating oils from constituents of high boiling residual hydrocarbonfraction heretofore considered unsuitable for such purposes. Anotherobject of this invention is directed to the method for upgrading adeasphalted residual oil extract phase to wide temperature range andmultiple viscosity lubricating oils,

Still another object of this invention is directed to hydrocracking theresinous extract separated in the preparation of Bright stock to provideoil fractions which may be blended to desired lubricating oils.

In accordance with this invention, a relatively high molecular weightresidual material comprising a resinous extract and aromatics eitherwith or without waxy constituents are derived from a relatively highboiling hydrocarbon fraction, particularly an asphalt free ordeasphalted petroleum residuum is passed with hydrogen to ahydrocracking zone maintained under relatively severe hydrocrackingconditions. During the hydrocracking step, the resins, `aromatics andany waxy constituents are upgraded to quality materials comprisinglubricating oil, fuel oil and naphtha boiling range materials. The thusprepared lubricating oil boiling range material is thereafter separatedby fractionating under vacuum conditions into desired viscosity boilingrange product fractions and thereafter dewaxed to provide desiredspecific pour point lube oil or wide temperature range lubricantssuitable for jet engines and hydraulic liuids.

It has been found quite unexpectedly lthat when a waxy bottom producthaving an initial boiling point of about 650 F. recovered from the totalliquid product effluent of the hydrocracking step and further separatedinto a plurality of separate boiling range fractions that dewaxingconditions for removing wax from the individual fractions need not be assevere as normally required. That is, subjecting the particularfractions lthus obtained to F. dewaxing conditions produced 0 F. pourpoint oil rather than a 20 F. pour point oil as would be normallyexpected. Generally speaking, and particularly when employing a feedmaterial containing waxy constituents, it is preferred to employ lowerproduct dewaxing temperature selected from within the range of yfromabout minus 65 F. to about minus 80 F. to produce oils having a pourpoint of at least minus 25 F.

In a more particular aspect, it has been found that a resin extracteither with or without waxy constituents and recovered from a cylinderstock in the prepartaion of Bright stock may be hydrocracked in thepresence of hydrogen and a hydrocracking catalyst maintained at atemperature in the range of from about 720 F. to about 850 F.; ahydrogen partial pressure in the range of from about 800 p.s.i.g. toabout 3,000 p.s.i.g.; a space velocity in the range of from about .05 toabout 1.5 v./v./hour and preferably below .8 V./V./hour to usefulupgraded products including a high boiling range material suitable forpreparing lubricating oils, fuel oil, and light and heavy naphthaboiling range materials.

The resin extract feed which is employed in the process of thisinvention is derived from a petroleum residuum by a number of -methodsknown in the art which involve solvent treatment of the residuum. Resinextract contains large proportions of petroleum resins which arehydrocarbons similar to asphaltenes except that they are not oxidized orcombined with sulfur and therefore are soluble in petroleum ether. Theresin extracts contemplated in the process of this invention have aviscosity at 210 F. of above about 700 SSU and can range as high asabout 4100 SSU or higher and preferably in the range of between about800 to 2000 SSU. Resin extract is commonly obtained by a multi steptreatment of residuum with a low boiling paraiinic hydrocarbon, as forexample, butane, propane or pentane. In this treatment, the asphaltportion of the residuum is first separated therefrom and thereafter thedeasphalted oil is treated with solvent to obtain the resin extract andan oil which is both deasphalted and deresined. Y

Although a paratiin base crude is preferred as the starting material foruse in the -method of this invention, other feed stocks may be usedincluding relatively high boiling deasphalted residual fractions 'fromwhich a resin extract either with or without waxy material can be obutained. Accordingly, the starting petroleum charge stock can be anydeasphalted petroleum residual fraction from which parainic andnaphthenic constituents are removed having resinous and aromaticconstituents therein and which may or may not have been subjected topartial or complete dewaxing at a temperature of about 0 F. Thismaterial either with or without wax constituents is the preferredhydrocarbon feed employed in the process of this invention. The waxconstituents of the resin extract comprise essentially microcrystallinewax.

In a more particular aspect, destructive hydrogenation and/0rhydrocracking conditions employed in the method 0f this invention aresuicient to convert a resin extract containing feed material and thoseconditions embody relatively severe carbon-carbon bond cleavagehydrocrack conditions in the presence of a gas exerting a hydrogen totalpressure of at least about 1,500 p.s.i.g. and preferably about 2,500p.s.i.g.; a temperature below about 810 F. and preferably about 770 F.while employing a hydrogen to hydrocarbon feed ratio of at least aboutto 1 mole ratio and a space velocity below about .8 v./v./hour andpreferably below about .3 v./v./hour. That is, a non-isomerizinghydrocracking catalyst of the type such as Co Mo Zr. Si may be employedor a hydrocracking catalyst exerting an isomerizing effect such as aPt=A1 catalyst promoted with from about 3-7 percent fluorine may beemployed particularly when the resin extract contains appreciable wax.

The catalyst which may be employed in the hydrocracking step of thisinvention may be substantially any of the known catalysts which promotethe hydrocracking reaction desired. It is preferred, however, to employan acidic hydrocracking catalyst promoted with a Group` VIII metalcomponent. Other suitable hydrocracking catalysts include the oxides andsuldes of the metals of Group VI or mixtures thereof such as chromiumsulde, molybdenum sulfide, tungsten sulfide and the like; oxides andsuldes of Group VIII or mixtures thereof such as iron, cobalt, nickel,palladium, platinum, rhodium, osmium, iridium, or mixtures of one ormore components selected from Groups VI and VIII of the Periodic Table.These materials and mixtures thereof may be deposited on a suitablecarrier material, preferably, an acidic carrier material such. as silicaalumina, silica zirconium, and alumina promoted with boria and/ or ahalogen promoter such as bromine, chlorine, and iluorine.

The total liquid product obtained from the hydrocracking process hereindescribed is separated under atmospheric distillation conditions toobtain a bottoms fraction having an initial boiling point of at least600 F. and preferably about 650 F. which is thereafter separated undervacuum distillation conditions to obtain a plurality of separate boilingrange fractions suitable for blending to desired lube oils. Depending onthe producer, the overhead liquid hydrocracked product may be separatedto recover a fuel oil from a light and heavy naphtha boiling rangeproduct.

EXAMPLE I n The following table shows the properties of typical resinextracts which can be employed in the process of this invention.

Resin extract A of Table I was hydrocracked over a platinum on silicazirconia catalyst (87.7 wt. percent Si02, 11.8 Wt. percent ZrOz, 0.5 wt.percent Pt) under the following conditions.

TABLE H Pressure p.s.i.g 3,000 Temperature F 750 Space velocity v./v./hr0.2 H2 circulation SCF/B 10,000

The reaction consumed hydrogen in an .amount of 1215 SCG/ B of charge.About 50 volume percent of the charge was converted to material boilingbelow 650 F. The product was distilled to obtain the followingfractions.

TABLE III Fraction Boiling Range, F. Percent Weight 0i Product LightNaphtha -180 4.1 Heavy Naphtha -390 19. 5 Gas Oil 390-600 23. 6 WaxyBottoms 600+ 52.8

The waxy bottoms product having an initial boiling point of about 600 F.is vacuum retorted or separated into a plurality of separate boilingrange fractions including a heavy bottoms fraction as shown in Table IVpresented below and having the physical properties indicated.

TABLE IV Cut No 1 2 3 4 5 6 7 8 Boiling Range, F (i60-825 825-870870-925 S25-995 995-1, 045 1, 045-1, 100 1, 100-1, 135 1,135+ WaxyFractions: Pour Point, F 30 35 50 60 70 65 6 Viscosity:

KV at:

100 F 7. 7 9. 4 11. 2 23. 3 33. 9 67. 6 607 210 F-- 2. 2 2. 6 2. 9 3. 64. 7 6.7 9. 6 44. 5 SSU at:

100 F 51.1 56.9 63.3 112 181 313 2, 813 210 F 33. 7 34.8 35. 9 38. 2 41.6 48. 1 57. 9 208 VI 105 112 117 135 132 124 11 Flash Point: Cut 1, 340F.; Cuts 2, 3, 4, 5, 6, 395 F. (SSU 39.3); Cuts 3, 4, 5, 6, 7, 410 F.(SSU 42.4).

Table V below identifies a plurality of lube oils prel 6 maintained at atemperature in the range of from about pared from blends of the oilfractions presented in Table IV. That is, Sample 1 of Table V was`obtained by blending cuts 2 ot 8 of Table IV; Sample No. 2 of Table Vis the same blend as Sample 1 but dewaxed at a temperature of minus 35F.; Sample No. 3 of Table V is a blend of cuts 2 to 6 and then dewaxedat minus 35 F.; Sample No. 4 is a blend of cuts 3 to 7 yof Table IVwhich Was dewaxed at minus 35 F.; Sample No. 5 is -a blend of cuts 3 to8 of Table V; and Sample No. 6 is a blend of cuts 5 to 8 of Table IV.

100 to about 105 F. for the purpose of separating relatively hardasphaltic material from the feed for removal from the bottom of zone 6by conduit 8. A deasphalted rafiinate is recovered from the upper partof zone 6 by conduit 10, combined with additional propane solventintroduced by conduit 12 and the mixture thus formed is passed to asecond propane extraction treating zone 16 maintained lat a temperaturein the range of 100 to 140 F. wherein a separation is made betweenparain components and resin components combined with aromatic TABLE V.LUBE OIL BLENDSTIXIIIEAIRED FROM OIL FRACTION OF Sample No 1 2 3 4 5 6Dewaxing Temp. F 0 35 35 35 0 0 ASTM Pour, F.. 0 10 25 20 0 10Viscosity:

SS U at:

100 F 90 113 337 704 210 F 39. 2 4l. 7 61. 8 89. 1

at: 100 F 18. 21 23. 65 72.8 151. 9 210 F 3. 94 4. 71 10. 7 17. 8 20 F..1, 350 1, 800 13, 000 36, 000 F.. 2, 500 3, 300 28, 000 75, 000 F.. 5,000 7, 500 60, 000 180, 000 65 F.. 47, 000 65, 000 700, 000 2, 000, 000Viscosity Index 130 13 124 Presented below in Table VI arespecifications and characteristics of wide temperature range lube oilswhich may be prepared by blending and dewaxing the oil fractions ofTable IV obtained by the method of this invention:

TABLE VI.-P]EIYSICAL SPECIFICATIONS OF ENGINE LUBRICANTS Type 1 2 3 4Speed in Mach 0. 9 2. 4 2. 4-3. 0 3.0-3.5 3.0-3.5 Temp. Range of Use, F.to... 350 450 500 500 Physical Requirements: Viscosity:

KV at:

500 F 1. 0 1. 4 400 F 1. 0 2. 7 210 F-- 3. 0 (3) (5. 6) 12. 1 100 F-.11. 0 (12. 4) (34) 30 F- 13, O0 30,000 65 I 13, 000 21, 000 Iour, F (max75 75 40 50 Flash 400 425 500 505 Firc,F 540 Spontaneous Ignition, F 750(1) 750 Volatility:

Percent Evaporation at 400 11,6% hrs. 35 15 Percent Evaporation at 500F., 6% hrs 10 6. 7

1 Report.

As a means of providing a better understanding `of the method andsequence of process steps of this invention, a diagramatic owarrangement of the process and method of operation is provided by Way ofexample in the figure. In the drawing, an asphalt containing residualoil in conduit 2 is combined with a solvent material such as propaneintroduced by conduit 4 to form a mixture which is thereafter introducedinto a propane deasphalting zone components. That is, normal paraflinsand isoparaflins combined with naphthenic material in the-feed will beremoved overhead as a rainate from Zone 16 by conduit 18. The resinextract containing aromatic either with or without waxy material isthereafter removed ias an extract phase by conduit 20 `for furthertreatment as hereinafter described.

In the event that a non-asphaltic crude `oil is employed as feedmaterial in the process or a residual fraction thereof, such as acylinder stock obtained from va paranic Pennsylvania crude, provisions.are made for bypassing deasphalting zone 6 by introducing theparat-linie feed stock such as a cylinder stock to the proc ess byconduit 14 communicating with conduit 10. If desired, however, dewaxingof the oil feed may be effected before or after the propane treatingstep accomplished in zone 16 of the process although as pointed outherein, it is not absolutely essential to dewax the feed and in somecircumstances, it is preferred to employ a waxy feed ma# teri'al. Whenemploying `a waxy -feed material, it is preferred to employ a catalystpromoting hydrocracking .and hydroisomerization reactions such as aplatinum-alumina catalyst promoted with a halogen promoter.

The use of propane for removal of resinous materials in the residualyoil permits the sorting ont, particularly from a high boiling asphalticcrude of the desirable constituents which go into making up a goodresidual oil boiling range material known as a Bright stock.

In accordance with this invention, an extract phase is recovered fromzone 16 by conduit 20 comprising resinous material and aromatics eitherwith or without waxy material which forms the particular and desiredfeed material of this invention. The resinous extract phase in conduit20 is combined preferably with excess hydrogen rich gas introduced byconduit 22 and the thus formed mixture is passed to a hydrocracking zone24. Hydrocracking zone 24 is controlled and maintained undersufficiently severe hydrocracking conditions to effect hydrocrackingwith or without hydroisomerization of the resin containing extract. In aspecific embodiment, hydrocracking conditions include a temperature ofabout 750 F., a pressure of about 3,000 p.s.i.g., and a space velocityof about 0.2 v./v./hour. The total liquid product produced by andobtained from the above hydrocracking step is recovered and passed byconduit 26 to distillation zone 28 for initial separation therein,preferably under atmospheric conditions into a light naphtha fractionfor withdrawal by conduit 30, a heavy naphtha fraction for withdrawal byconduit 32, a fuel oil fraction boiling in the range 375- 650 F. forwithdrawal by conduit 34 and a bottoms fraction having an initialboiling point of about 650 F. for withdrawal by conduit 36. The highVboiling bottoms fraction boiling above the fuel oil boiling rangematerial is withdrawn by conduit 36 and passed to zone 38 wherein it issubjected to vacuum distillation conditions sufficient to produce aplurality -of separate boiling range fractions comprising in a specificexample eight separate fraction-s similar to those identified by Table 1above. The eight separate fractions have been diagrammatically shown asbeing withdrawn or recovered through conduits 40 to S4 respectively fromzone 38. The separate cuts or fractions 1 to 8 identified in Table IVand lwithdrawn through conduits 40 to 54 respectively were eachsubjected to separate dewaxing steps in zones 56 to 70 respectively atdewaxing conditions in the range of from about F. to about minus 80 F.It was found, however, quite unexpectedly that 0 F. dewaxing conditionscould be employed to produce 0 F. pour point oil when employing a resinextract feed substantially free of waxy constituents.

It is contemplated employing, however, particularly when converting waxyfeed materials, lower temperature dewaxing conditions, as low as minus80 F., in any one or all of the `dewaxing Zones 56 to 70 shown so thatdesired pour point oil fractions may be recovered through conduits 72 to86 respectively. In the method of this invention and particularly whenemploying dewaxing temperatures of the order of about minus 65 F. andlower, the waxy material separated therein and recovered from theplurality of dewaxing zones 56 to 70 by conduits 88 to 100 is passed byconduit 102 to a common deoiling zone 104 wherein, for example, a 20 F.pour point high VI oil may be separated from the waxy constituentspreviously separated at temperatures below minus 65 F. Generally, thedeoiling step will be accomplished at a temperature of about 0 F. Thehigh VI oil recovered in zone 104 is removed therefrom by conduit 106with the remaining wax being recovered at 108.

Having thus presented a general description of the improved method andsequence of process steps of this invention and set forth specificexamples relating thereto, it is to be understood that minormodifications may be made thereto without departing from the scopethereof and no undue restrictions are to be imposed by reasons of thespecific examples presented.

We claim:

1. A method for producing lubricating oils which comprises recovering aresin extract having a viscosity at 210 F. of between about 700 SSU andabout 4100 SSU of a substantially asphalt-free residual crude oil,catalytically hydrocracking the resin extract under conditions toproduce naphtha boiling range material, fuel oil and a high boilinglubricating oil fraction, separating by fractionation and dewaxing thehigh boiling lubricating oil fraction into a plurality `of oil fractionsof different boiling range and thereafter combining portions of thelubricating oils of different boiling range to produce a desiredlubricating oil.

2. A method for producing lubricating oil which cornprises recovering aresin extract having a viscosity at 210 F. of between about 700 SSU andabout 4100 SSU of a substantially asphalt-free residual crude oilcomprising aromatics and resins, hydrocracking the extract phase Iunderrelatively severe hydrocracking conditions in the presence of ahydrocracking catalyst, recovering a lube oil product having an initialboiling point above about 600 F. from the hydrocracking step, separatingthe high boiling lube oil product under conditions to obtain a pluralityof separate lube oil fractions of different boiling range and thereafterseparately dewaxing the lplurality of lube oil fractions to obtain aplurality of 0 to 20 F. pour point lube oils.

3. The method of claim 2 wherein the resin containing extract lphase isobtained from an asphalt containing residual oil fraction by contactingthe residual oil with a solvent in a plurality of steps.

4. The method of claim 1 wherein the dewaxing is carried -out at atemperature selected from within the range of from about 0 F. to aboutminus 80 F.

5. The method of claim 1 wherein the resin extract contains waxymaterials.

6. The method of claim 1 wherein the resin extract is dewaxed prior tobeing subjected to catalytic hydrocracklng.

7. The method of claim 1 wherein the residual oil comprises a parafnicnon-asphalt residual oil.

8. The method of claim 1 wherein dewaxing of the separated lubeoilfractions of different boiling range is effected at a temperatureless than minus F. and the waxy constituents obtained therefrom isdeoiled at a temperature of about 0 F.

9. The method yof claim 2 wherein a dewaxed resin extract is the feed tothe hydrocracking steps and 0 F. pour point lube oils are preparedtherefrom by effecting dewaxing of the hydrocracked product lube oilfractions at a temperature of about 0 F.

References Cited UNITED STATES PATENTS 2,960,458 11/1960 Beuther et al.208-19 2,967,146 1/1961 Manley 208-87 3,046,218 7/1962 Henke et al.208l9 3,142,634 7/ 1964 Ireland et al 20895 DELBERT E. GANTZ, PrimaryExaminer.

HERBERT LEVINE, Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3 ,328,287 June Z7 1967 Michael T. Smilski et al.

It is hereby certified that error appears in the above numbered patentrequiring correction and that the said Letters Patent should read ascorrected below Column 3, lines 6l and 62, for "hydrocrack" readhydrocrackng column 3, line 7l, for "Pt=Al" read P11-Al column 4 line 58for "SCG/B" read SCF/B columns 5 and 6, in Table IV, ninth column, line7 thereof, for "ll" read ll5 column 5, line 18, for "ot" read to Signedand sealed this 18th day of June 1968.

(SEAL) Attest:

Edward M. Fletcher, Jr. EDWARD J. BRENNER Attesting Officer rCommissioner of Patents

1. A METHOD FOR PRODUCING LUBRICATING OILS WHICH COMPRISES RECOVERING ARESIN EXTRACT HAVING A VISCOSITY AT 210*F. OF BETWEEN ABOUT 700 SSU ANDABOUT 4100 SSU OF A SUBSTANTIALLY ASPHALT-FREE RESIDUAL CRUDE OIL,CATALYTICALLY HYDROCRACKING THE RESIN EXTRACT UNDER CONDITIONS TOPRODUCE NAPHTHA BOILING RANGE MATERIAL, FUEL OIL AND A HIGH BOILINGLUBRICATING OIL FRACTION, SEPARATING BY FRACTIONATION AND DEWAXING THEHIGH BOILING LUBRICATING OIL FRACTION INTO A PLURALITY OF OIL FRACTIONOF DIFFERENT BOILING RANGE AND THEREAFTER COMBINING PORTIONS OF THELUBRICATING OILS OF DIFFERENT BOILING RANGE TO PRODUCE A DESIREDLUBRICATING OIL.